Yes!

We are using Zimbra 7.1.2 network edition running on RHEL 6 x86_64 on top of RHEV 2.2 here at Red Hat. We are planning to move to RHEV 3.0 soon. It works very well. The only potential word of caution that I would have is to architect in such a way that your OS lives in the RHEV storage pool, but your Zimbra specific files (contents of /opt/zimbra) live on some other dedicated storage. We use a Netapp filer presented via ISCSI. There are many reasons for this, but one of the main ones is that our environment is too large for the built in Zimbra backups to be able to complete in a timely manner. We use Netapp snapshots instead. Any more questions, let me know.